Sealing of Porous Anodic Film by Cerium-Conversion Coating on AA2024 Aluminum Alloy: Study on the Anticorrosion Performance

In this study, we report investigation on the synergistic effect efficiency between anodizing process and cerium-based conversion deposit (CeEC) on the corrosion behavior of 2024-T4 aluminum alloy substrate. Structural and chemical details were revealed by the X-ray diffraction (XRD) and Raman microscopy. The synergistic effect efficiency against corrosion of 2024 Al-alloy in contact with aerated 3.5 wt.% NaCl solution was clearly evidenced from the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS), over a wide frequency domain (1 MHz-1 mHz). The polarization resistance (> 10(5) k omega cm(2)) and the inhibiting efficiency (> 97%) obtained for the Al-alloy specimen undergoing both anodizing and CeEC deposit reveal outstanding anticorrosion properties, in contrast to the CeEC-treated and untreated samples.